Electrical circuit device



Jan- .22 1957 w. o. McFARL-AND 2,778,992

ELECTRICAL CIRCUIT DEVICE Filed Nov. 6. 1953 IN VEN TOR.

WILUHM O. MCFHRLHND HTTORNEY United States Patentl ELECTRICAL CIRCUIT DEVICE William 0. McFarland, Newton Faits, Ghia Application November 6, 1953, Serial N o. 390,549

3 Claims. (Cl. 324-51) The present invention relates to an electrical circuit device, more particularly to a pocket-type electrical circuit tester and the principal object of my invention is to provide new and improved devices of the character described.

A so-called pocket-type electrical circuit tester in common use at the present time comprises a body which is adapted to support a small neon lamp. A pair of flexible leads are electrically connected to the lamp and each extends from the body and has its free end provided with a probe. This prior art device has been more or less satisfactory in use; however, carrying the device presents a problem since the probes are exposed and can very easily injure the user if the device is carried in a pocket.

While l am aware thatV attempts have been made to protect the probes of such devices by enclosing them within a housing of some description, these devices have met with failure because they were expensive to manufacture and rather awkward to use.

My invention provides a device which is relatively inexpensive to manufacture, extremely handy in use, and one which offers complete protection to the user since the probes are completely enclosed when the device is carried in a pocket. These and other advantages will become apparent from a study of the following description and from the drawing appended hereto.

ln the drawing accompanying this specification and forming a part of this application there is shown, for purpose of i-llustration, an embodiment which my invention may assume, and in this drawing:

Figure 1 is a perspective view of my improved pockettype electrical circuit tester,

Figure 2 is an enlarged view in longitudinal section of the device shown in Figure 1, certain parts being separated to more clearly illustrate the invention; and

Figure 3 is a fragmentary view similar to Figure 2 but showing certain parts in another position.

As illustrated in Figure 1 wherein my invention is shown in assembled relation for storage in a users pocket or the like, my device comprises an elongated pencilshaped body i@ having a ilexible, insulated conductor 11 extending from one end of the body to the other end thereof. A clip 12, which will later be described in detail, is carried by the body 10 and cooperates with the body to provide a clip for retaining the device within a users pocket.

As best shown in Figure 2, the body 10 is presently formed of a pair of tubular members 13, 14 formed of transparent plastic or the like. Respective abutting ends 15', 16 of the members 13, 14 are presently formed by cutting the members on a bias or at an oblique angle with respect to the longitudinal axis thereof. It will be clear that the edges 1S, 16 are formed at the same angle so that such edges will be complementary to each other. lt will readily be apparent that the members 13, 14 may be formed from a single tubular member of the proper length simply by cutting through such tubular member to provide two pieces which will then become members 13, 14. Although it is presently preferred to form the edges 15, 16 at the acute angle shown so as to increase the bearing area when the members are positioned together, any other angle (including an angle of with respect to the longitudinal axis) could be employed if desired.

As best shown in Figure 2 and in the `embodiment herein disclosed, respective abutting ends of the members 13, 14 are closed by respective Walls or plugs 17, 18 secured within a respective member by any suitable means. As illustrated, the terminal portion of each plug 17, 1S adjoining respective surfaces 15, 16 is formed to lie in the same plane as a respective surface.

ln the present embodiment, a probe 19 is adapted to be anchored in each of the plugs 17, 18 by any suitable means and each probe is adapted to extend axially and outwardly of its respective member. It is presently preferred to locate each of the probes at a point adjacent the longest dimension of a respective member 13, 14, as shown, in order to facilitate use of the device in a manner to be described. Each of the plugs 1'7, 18 is apertured at 2o to slideably and preferably frictionally receive the extending portion of the probe 19 carried by the opposite plug.

In the presently disclosed embodiment, each of the tubular members i3, 14 has a plug 21 secured in the end thereof opposite the respective abutting surfaces 1S, 16 and each plug 21 is apertured to pass the flexible con ductor 11. in the space thus provided in the member 13 between the plug 17' and the respective plug` 21, a smail neon lamp 22 is positioned. As illustrated, the lamp 22 has electrical connection with the probe 19 carried by the plug li' and also with the adjoining end of the conductor 11. ln the space provided in the member 14 between the plug 1S and the respective plug 21, the usual resistor 23 may be positioned. The resistor may be electrical-ly connected to the probe 19 carried by the plug 1S and also with the adjoining bared end of the conductor 11.

The previously mentioned clip 12 (see Figures 1 and 2) comprises, in the presently disclosed embodiment, a portion 24 which is adapted to at least partially encircle the member 13 and to frictionally engage therewith. A generally U-shaped spring member 25 is adapted to have one leg secured to the portion 24 and the other leg se- '1 cured to an arm 26. A portion of the arm 26 is provided with an abutment 27 and the arrangement of the clip portions are such that the spring member 25 urges the abutment 27 carried by the arm 26 toward engagement with the member 13. It will be appreciated that any other type of slidable clip may be used, if desired.

When the device is assembled for carrying relation as shown in Figure 1, the clip 2S may be employed to clip the device to a pocket or the like in a manner which will be clear.

In using the device for testing purposes, the members 13, 14 may be separated, as shown in Figure 2, and each of the probes 'i9 placed in contact with respective lines of the circuit to be tested in the usual manner. As with conventional testers of this general type, the neon lamp 22 will glow if the circuit being tested is carrying electrical current.

It is sometimes desirable when testing circuits to employ only one hand for manipulation of the tester. This is difficult if not impossible when using conventional type devices; however, my invention provides for easy onehand manipulation.

As shown in .Figure 3, the clip 12 may be employed in conjunction with the probe 19 carried by the member 13 to provide a clamp for removably securing this probe in place during testing. With the construction hereinbefore disclosed, it is only necessary to slide the portion 24 of the clip 12 toward the end of the member 13 carrying the probe 19 until the portion 27 of the arm 26 engages with this probe. It will readily be apparent that pressure maybe applied to the arm 26 to deflect the spring 25 and open the jaws provided by the abutment portion 2'7 and the respective probe 19, the jaws positioned about the terminal or the like which forms a part of the electrical circuit to be tested, and the arm 2e then released whereuponV the member 13 will remain firmly clipped to the terminal or the like with no further manipulation. The member i4 may then be manipulated with one hand to position the probe 19 carried by this member in contact with the other part of the circuit being tested.

While the use of only one clip J"i2 has been shown and described, it will be obvious that another clip l2 could be carried by the member 14 for cooperation with the probe 19 carried by this member.

In order to re-assemble my invention for a pocket or the like, it is only necessary to position the clip 12 in the position shown in Figure 2 and to position thc members 13, 14 in end-tc-end abutting relation as illustrated in Figure l, by inserting each probe E9 in its rcspective aperture 29.

ln view of the foregoing it will be apparent to those skilled in the art that I have accomplished at least the principal object of my invention and it will also be apparent to those skilled in the art that the embodiment herein described may be variously changed and modified, without departing 'rom the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described, hence it will be appreciated that the herein disclosed embodiment is illustrative only, and that my invention is not limited thereto.

I claim:

l. Means for testing electrical circuits, comprising a pair of complementary cylindrical members arranged in end to end abutting relation with the line of abutment disposed at a bias in a single flat plane to facilitate assembly, each of said members being substantially closed at its 4 Opposite ends by longitudinally spaced closure plugs of insulating material, each of said members having an elongated current conducting probe housed within and projecting longitudinally from a said closure plug at the inner abutting end of the member, said plugs at said inner abutting ends of the members each having a longitudinal aperture for receiving the projecting end of a said probe to protect the probes when said members are disposed in abutting and connected relation, a current tlow indicating circuit having cooperating portions thereof housed within each of said cylindrical members between said closure plugs and respectively electrically connected to the inner ends of said probes, and a flexible insulated conductor wire having its opposite ends projecting through said closure plugs at the opposite non-abutting ends of said members and electrically connected to said current ow indicating circuit.

2. Means for testing electrical circuits as defined in claim l, wherein a spring retracted pocket clip is slidably mounted on one of said members, said clip having a longitudinally projecting end for yieldable cooperation with the exposed end of said probe on said one member to resiliently hold therebetween a portion of the electrical circuit to be tested.

3, Means for testing electrical circuits as defined in ciaim l wherein said probes and their plug receivingl apertures are each of cylindrical cross section and said apertures are of substantially the diameter of the probes for snugly and frictionally receiving the latter therein.

References Cited in the file of this patent UNITED STATES PATENTS 2,276,736 Olson Mar. 17, 1942 2,458,628 Okun Jan. 11, 1949 2,479,186 Simkins e Aug. 16, 1949 2,675,528 La Point Apr. 13, 1954 

